While a hot natured person can feel hot and a cold natured person can feel cold the hot natured and cold natured also has another meaning.
The other meaning of a hot natured person is they are highly emotional and impulsive.
The cold natured person would be unemotional and unsympathetic.
Even when bodies are the same size, the amount of body fat inside can vary and affect how cold or hot we feel in comparison to others.
The greater the amount of body fat, the warmer one feels.
Older people often might feel colder than younger people, as the fat layer under the skin that conserves heat thins with age.